Well, I had a brief session with my friend's IPad with the 'SPL Meter' App installed. What a cool device - I may have to get one!

Assuming that it is reasonably accurate, my sound level comfort level (when I'm sober, ha1) is about 75 Dbs Average with the absolute max being 85 Dbs Average.

Spiro Gyra 'Good to Go-Go' SACD is recorded very hot. At my seating area of 8 to 9 feet, my tube-amp levels (o'clock) gave me roughly:

* 10 o'clock - 75 Db Ave / 79 Db max;

* 11 o'clock - 85 Db Ave / 88 Db max.

At the back of the room 25' away from the speakers:

* 10 o'clock - 70 Db Ave / 75 Db Max;

* 10 o'clock - 80 Db Ave / 82 Db Max.

The Cameron Carpenter SACD is recorded at a much lower average level that gave me 65 Dbs Ave / 70 Db Max in the listening area.

According to the specs that I've read on the output of the EP-400, I must conclude that it could capably do the job for my audio only system in my setting by providing more than adequate, clean & accurate bass response.

Thanks to all for your interest & assistance. Comments are most welcome...

In my haste to send send my SPL results for my main audio system, I forgot that I had taken some readings for my M3v3 'ambiance system' in the same room.

We played Wynton Marsalis & Eric Clapton 'play the blues' CD - 'Layla' - on my simple, solid state Sony 90 Watt/Channel, 2 Channel Receiver. I normally run it between 25 & 35 on the Volume Level. Readings were taken midway between the M3s in opposite corners that are 30' apart. We recorded the following SPLs:

* Vol Level 30 - 70 Db Ave & 75 Db Max (moderate level);

* Vol Level 35 - 75 Db Ave & 80 Db Max (just becoming too loud).

My friend was most impressed with the M3's sound. Nice sentiments considering that he is a musician...

Tom, your results indicate that the levels you actually use will be no strain on your M2s, EP400, amplifier, and most importantly, your hearing.

An especially interesting result to me was the comparison of the levels at your listening position and at the back of the room. The studies of Dr. Toole and others which indicate about a 3dB lower level per doubling of distance in typical home listening rooms have been mentioned here several times. In your case the back measurement at 25' was not quite two distance doublings and about a 5dB lower level would be expected. Your results do indeed show that difference, varying from 4dB to 6dB. That app may in fact deliver reasonably accurate results.

Using the 'SPL Meter' App was great fun. If you have an iphone, this App works with it as well. It knows what hardware that it is working on & applies the right mic correction. Well worth The $0.99.

I had a typo the last 'back' reading - it should have been 11 o'clock vise 10.

I talked to Brent ref my purchase. He said that I was lucky to have come across an EP-400 on the factory clearance as they are quite rare - that's why I jumped on it. Brent has one in his own system & loves it...